Merritt Island's little-used safety, Stan King, intercepted a pass by Apopka quarterback Keith Ussrey on the Mustangs' 30-yard line with 1:11 left in the game to clinch Merritt Island's upset.

The Darters (10-1) had moved 32 yards in six plays in just more than a minute in the final Apopka series before King, playing in his third game of the season, made his first interception of the year. Three times Apopka had fought off third-and-long situations before King's interception abruptly ended the Darters' quest for an unbeaten season.

It was the sixth consecutive victory for Merritt Island (8-3). The Mustangs beat Apopka at its game on its field -- ball-control offense. While the Merritt Island Wishbone offense was steadily grinding time off the clock, the Darters' offense sat helplessly on the sideline waiting for a chance to play. The Mustangs held Apopka's highly touted tailback, Mike Lowman, to 33 yards rushing and no touchdowns on nine carries. Ussrey completed 11 of 18 passes for 129 yards.

''That's the only way we know how to play it,'' Merritt Island Coach Gerald Odom said. ''We had to control the football on offense and keep the ball away from them. It was a great team effort. We felt real good about coming in here and winning.

''We don't talk much about state rankings. They make good reading, but they don't mean anything when you line up across the football from the other team. They still had to beat us.''

Merritt Island middle linebacker Garrett Thompson recovered an Apopka fumble on the Mustangs' 45-yard line with 1:22 left in the third quarter for the deciding break that set up the winning touchdown.

Running back Randy Rigdon snapped a 7-7 deadlock with a 1-yard burst up the middle with 8:34 left to cap a 55-yard victory drive. Mark Boring kicked the conversion.

''We just couldn't get the break -- the fumble recovery -- they got,'' Apopka Coach Chip Gierke said. ''Our kids knew exactly what they were going to do, but the game comes down to blocking and tackling. It just turned out to be a matter of one play.

''I thought we were real close a couple of times, but we got out-executed. This team has nothing to be ashamed of. We'll just pick up the pieces and go on for '86.''

After a shaky first possession in which it was flagged for 30 yards in penalties, Merritt Island took early control of the offensive flow by running right up the middle at the heart of the Darters' defense. An encroachment penalty against the Apopka defense moved the ball down to Apopka's 10, and two plays later Rigdon put Merritt Island ahead with a 2-yard run with 8:20 left in the first half. Boring added the PAT for a 7-0 lead.

Danny Daniels brought Apopka sprinting right back with a spectacular 85- yard kickoff return, but it was partially negated by a clipping penalty. A face-mask penalty on Merritt Island a few plays later helped Apopka move to the Mustangs' 30-yard line.

After Lowman and fullback Charles Dowdell each contributed 8-yard runs, Lowman saved the drive with a clutch 4-yard pickup on 4th-and-2 for a first down at the 7. Three plays later, Ussrey capped the 10-play, 46-yard drive with a 1-yard sneak. Scott Reynolds tied the score, 7-7.

Merritt Island nearly scored on the final play of the first half. Price passed to Don McNeil, who gained 32 yards to the 5 before being tackled by linebacker Anthony Guice.

Merritt Island threw a scare into the Darters in the closing seconds of the half as Price connected on a 32-yard pass over the middle to Don McNeil. McNeil fought his way to the 5 and only a second-effort tackle by linebacker Anthony Guice brought him down short of the goal line as time expired.